Portion of a shoe sole



FIG. 1 is a first perspective view of a portion of a shoe sole showing my new design;

FIG. 2 is a second perspective view thereof; and,

FIG. 3 a plan view thereof.

The broken line showing of the remainder of the shoe is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a portion of a shoe sole, as shown and described. 